August 8, 2012: "Polar Bears May Have Survived 4-5 million Years of Climate Change" as reported by "Climate Change Reconsidered", The Website of the Nongovernmental International Panel on Climate Change (NIPCC).

"if these authors are correct that polar bears have existed as a distinct species for 4-5 millions years, it means they must have persisted through all of the more than 50 glacial cycles of the Pleistocene epoch, which lasted 2.5 million years (Gibbard et al., 2005). A number of the more recent cycles - during the last 1 million years - involved extreme swings in climate from quite warm, with much less summer sea ice in the Arctic than today, to extremely cold, with a mass of thick ice in the Arctic Basin and sea ice extending into the north Atlantic and north Pacific (Polyak et al., 2010). This suggests that the Arctic adaptations that make polar bears unique includes an ability to persist as a species through extreme swings in sea ice conditions."